It's just as carby but I don't use much. If you plan on reheating the stew, arrowroot isn't a good choice, by the way. It thickens quickly but thins back down if you heat it more.

Edit: I just checked calorieking.com and arrowroot and xanthan gum are pretty close in carb counts but you use about 1/3 as much xanthan gum for the same amount of liquid. Also, xanthan is apparently a corn product. Didn't know that.